package com.whc.myblog.service.impls;

import com.whc.myblog.dao.CommentRepository;
import com.whc.myblog.pojo.Comment;
import com.whc.myblog.service.interfaces.CommentService;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Sort;
import org.springframework.stereotype.Service;

import javax.transaction.Transactional;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

@Service
public class CommentServiceImpl implements CommentService {

    @Autowired
    private CommentRepository commentRepository;

    @Override
    public List<Comment> listCommentByBlogId(Long blogId) {
        Sort sort = Sort.by("createTime");
        List<Comment> comments = commentRepository.findByBlogIdAndParentCommentNull(blogId,sort);
        return eachComment(comments);
    }

    @Transactional
    @Override
    public Comment saveComment(Comment comment) {
        Long parentCommentId = comment.getParentComment().getId();
        if(parentCommentId != -1){
            comment.setParentComment(commentRepository.getById(parentCommentId));
        }else {
            comment.setParentComment(null);
        }
        comment.setCreateTime(new Date());
        return commentRepository.save(comment);
    }

    //循环每个顶级的评论点
    private List<Comment> eachComment(List<Comment> comments){
        List<Comment> commentsView = new ArrayList<>();
        for(Comment comment : comments){
            Comment c = new Comment();
            BeanUtils.copyProperties(comment, c);
            commentsView.add(c);
        }
        //合并评论的各层子代到同一级子代集中
        combineChildren(commentsView);
        return commentsView;
    }

    private void combineChildren(List<Comment> comments){
        for(Comment comment : comments){
            List<Comment> replies1 = comment.getReplyComments();
            for(Comment reply1 : replies1){
                //循环迭代，找出子代，存放在tempReply中
                recursively(reply1);
            }
            //修改顶级节点的reply集合为迭代处理后的集合
            comment.setReplyComments(tempReplies);
            //清除临时存放区
            tempReplies = new ArrayList<>();
        }
    }

    //存放迭代找出的所有子代的集合
    private List<Comment> tempReplies = new ArrayList<>();

    private void recursively(Comment comment){
        tempReplies.add(comment);//顶节点添加到临时存放点
        if(comment.getReplyComments().size()>0){
            List<Comment> replies = comment.getReplyComments();
            for(Comment reply : replies){
                tempReplies.add(reply);
                if(reply.getReplyComments().size()>0){
                    recursively(reply);
                }
            }
        }
    }

}
